


Inverse Stay Night

by DONTSALTME69



Series: Inverse Fate [2]
Category: Fate/Zero, Fate/stay night & Related Fandoms, Fate/stay night (Visual Novel), Fate/stay night - All Media Types
Genre: Action, Alternate Universe, Alternate Universe - Character Swap, Can be read without reading Inverse Zero, Canon-Typical Violence, F/M, Fifth Holy Grail War, Gen, Holy Grail War (Fate), Servant Swap, This is not connected to Inverse Zero beyond the reversal of the premise, What If the Fate/Zero Servants were in Fate/Stay Night?
Language: English
Status: In-Progress
Published: 2020-09-11
Updated: 2020-10-23
Packaged: 2021-03-06 16:20:34
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 4
Words: 6,212
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26391811
Author URL: https://archiveofourown.org/users/DONTSALTME69/pseuds/DONTSALTME69
Summary: What if the Servants of Fate/Zero were summoned in Fate/Stay Night? Would they bring the tradegy surrounding the Fourth Holy Grail War to the Fifth, or would things improve with their presence?
Relationships: Emiya Shirou/Matou Sakura
Series: Inverse Fate [2]
Series URL: https://archiveofourown.org/series/1917316
Comments: 9
Kudos: 41





	1. Lancer

When Diarmuid Ua Duibhne was summoned, he was immediately met with a horrific sight.

A dying woman with a severed arm, and a priest standing over her with said arm in his hand.

"Ah, so you are the Servant she wanted to summon." The priest stated.

Diarmuid summoned his spears to his hands, thrusting Gae Dearg for the priest's neck. His true Master was that woman. He was not going to allow that man who was killing her to control him.

Gae Dearg stopped just short of piercing the priest's throat. The first Command Seal has been spent.

The priest spent his second and third Command Seals on prevent Diarmuid from saving the woman, and on preventing him from committing suicide to spite him.

* * *

Diarmuid hated working for Kirei Kotomine. He was dishonorable man who didn't care who he hurt on the way to his goals. Well, no. He did care who he hurt. He cared about who he _didn't_ hurt.

The first battle Diarmuid had was technically before the war even started, against Archer at a high school. That one could barely be called a battle, merely Lancer dodging a barrage of projectiles until there was a witness to their battle that Kirei ordered him to dispose of.

He cornered the boy in a hall.

"I'm sorry." Diarmuid stated, before piercing the boy's heart with Gae Dearg.

* * *

He was forced to hunt down the boy and kill him by the priest, pursuing him to his house.

After a small skirmish, the boy managed to summon a Servant. The Servant was a Saber, who sent the Lancer flying out of the shed that the boy had ran to.

"Saber, I apologize for attacking your Master this way." Diarmuid said, bowing. "My Master is a dishonorable coward."

"I understand, Lancer. Let us do battle." Saber said, lunging. Diarmuid raised Gae Dearg to block her opening slash, countering with a thrust from Gae Buidhe. Saber stepped around him, dodging the attack and circling to his side and swiping her invisible sword at him.

Diarmuid narrowly dodged it, swinging Gae Dearg and forcing Saber to block it. He thrusted Gae Buidhe to follow up. It clanked off Saber's gauntlet, before she struck back with a slash that forced Diarmuid to step back and get a cut across the chest for his trouble.

"You're quite impressive, Lancer. I've never fought against one who uses his spears in such a way." Saber stated. "I hope we will be able to enjoy our battle to the fullest."

"I hope so too." Diarmuid said, before dropping Gae Buidhe. "I'm going to come at you with a different game plan. Do not mistake it for me holding back." He gripped Gae Dearg with both hands, lunging at Saber.

Diarmuid unleashed a barrage of lightning-fast thrusts with the demonic spear, forcing Saber on the defensive. She blocked a strike with her blade, attempting to parry. Diarmuid stepped back, before approaching again with another thrust. While Saber couldn't block this strike, she wasn't worried; expecting her armor to take the blow for her.

Gae Dearg slipped through the armor like it wasn't even there, cutting Saber's side. Saber swiped at Diarmiud, forcing him to get back.

They both saw that the sheath of air around Saber's sword was partially gone, allowing all to see the true form of her blade.

"No wonder you're so good." Diarmuid remarked. "You're the legendary King of Knights, Arthur Pendragon."

"Your lance ignores magic on its way to strike its target." Saber noted.

"It would not sit well for me to reveal your name and not tell you mine. I am Diarmuid Ua Duibhne, a hero of Irish Mythology."

Saber dispelled her armor, seeing no use for it against an opponent who can pierce through the magical metal. "Let us continue our battle."

And then she lunged. Saber was even faster than before, and the lack of armor getting in her way meant she was more flexible to add to it. Diarmuid barely managed to block her first strike, pushing off and attempting an offensive of his own. Saber parried, pushing her blade up and knocking Diarmuid off-balance.

Just as Diarmuid planned. He stomped on the ground, knocking Gae Buidhe up and into his hand, narrowly dodging Saber's thrust as he did so. He swiped the yellow spear at Saber's left arm, leaving a shallow cut along it that severed the tendon in her left thumb.

Saber swung her blade to force Diarmuid to get back. She attempted to speed her healing by burning mana, only to be surprised when the wound wouldn't close. "One lance pierces magical defenses, while the other creates wounds that will not heal." She realized. "A terrifying combination."

Before the conversation could continue, a thunderclap heralded the arrival of Rider, who barreled in between them on his chariot with a young girl riding with him. "I am Iskandar the Conqueror!" He bellowed, preparing a speech of some sort.

Archer materialized atop the shed, arms folded.

Diarmuid didn't get to hear what either of them had to say, as Kirei forced him to retreat before they could talk.

* * *

A few days passed without much incident, until Diarmuid finally saw them. A dark figure out in the city.

Assassin, the Servant that they couldn't find.

' _It must be_ his _Servant._ ' Kirei mused, across their telepathic connection. ' _Engage._ '

Diarmuid did so, sprinting up the building Assassin was standing on. At the very least, he and Kirei did agree on engaging Assassin immediately. Assassin leaned back as Diarmuid swung Gae Dearg, narrowly dodging the cursed lance.

The Lancer got his first good look at Assassin. A dark man with a white skull mask and a built physique. Assassin turned to the side and sprinted away, clearly trying to lure Diarmuid away.

Diarmuid knew this, and still pursued. There was a battle to be fought and won.

Assassin jumped from building to building, using his agility to his advantage to prevent Diarmuid from getting close enough to strike. The Lancer hurled Gae Dearg, which actually managed to nick Assassin in the arm. Assassin jumped off the building down onto the nearby highway, landing on a car transport truck.

Diarmuid jumped down to pursue, running along the highway. Assassin unhooked the rearmost car from the trailer, pushing it off into the Lancer's path. Most Servants would simply dodge it.

Assassin was not fighting an ordinary Servant. Diarmuid pierced the gas tank with Gae Dearg, before jumping over the car. The vehicle exploded, propelling Diarmuid over Assassin and onto the truck.

Their battle was short. Assassin threw quick, coordinated strikes that simply struck neither fast enough nor hard enough to truly harm Diarmuid before the Lancer could end his life.

"I would have expected him to take more punishment than this." Diarmuid thought out loud, before noticing another dark figure; standing atop a streetlight. This one looked different from the last, a woman instead of a man.

' _There are multiple bodies. Kill them with Gae Buidhe._ ' Kirei ordered. Diarmuid jumped off the truck, landing on the pavement. The new Assassin jumped down to meet him.

Diarmuid found something suspicious. Why bother to face him like this?

Assassin ran past him, sprinting up the side of a building. Diarmuid gave chase, catching up in moments and landing on the roof. He was met with at least ten Assassins, all similar yet different. They were all headed in the same direction, but weren't able to move as fast as the first Assassin was.

No. They were as fast as he was, but they weren't as agile as him. Diarmuid chose a target and focused on them first. Trying to go after all of them was an exercise in futility. He threw Gae Buidhe into his first target's back, spearing them through the heart.

Sprinting past the fading corpse, he retrieved Gae Buidhe and switched focus to his next target. As they jumped across buildings, Diarmuid intercepted them mid-air and sliced them with Gae Buidhe. Another one entered his path right as he landed, getting impaled Gae Dearg for their efforts.

* * *

Diarmuid systematically killed them one by one while in pursuit. Perhaps they wouldn't all die today, but the losses would be impactful. Fourty were killed, thirty of whom were slain by Gae Buidhe.

Simply put, there was no way to recover those thirty without Diarmuid's destruction. This made him feel slightly more confident as the Assassin ran into a forest just outside city limits. The Assassins seemed to slow down, some outright turning around and rushing him. They stopped just outside his reach. It was strange. He wanted to just dispatch them.

But his instincts were telling him to get out of there. It did not help that Kirei had gone completely silent. One stepped forward, throwing a few quick strikes. Diarmuid killed them with one thrust of Gae Dearg.

Why was he so anxious? What was it that bothered him about this so much?

That's when _it_ appeared. A dark monster. The Shadow, as he had internally named it. It moved faster than expected, wrapping a tentacle around his leg while he was distracted. The tentacle didn't break when Diarmuid slashed it with his spear. A cursed lance wouldn't do much against a cursed being.

It pulled him in violently, causing him to drop Gae Buidhe, before beginning to absorb him. Diarmuid felt the pull of a Command Seal trying to warp him out of there, but just couldn't go. This thing could stop the magic of a Command Seal.

Nothingness overtook Diarmuid, and he lamented his failure as a knight. He failed to save his true Master, nor could he even fulfill the wishes of the one who stole her position.

* * *

Kirei was annoyed. He had lost Lancer in the process of information gathering. It wasn't a critical loss, but a bad one at this stage. He heard a clank on the ground, turning around to see a yellow spear on the floor.

At least Lancer's death wasn't entirely in vain. He picked the weapon up, preparing to do what he has to to keep it in this world for as long as possible.

Zouken thinks he has the advantage in this Holy Grail War.

Kirei begged to differ.


	2. Caster

If there was one word that the Master of Gilles de Rais, Atrum Galliasta, would use to describe his Servant, it would be _disturbing_.

He supposed he should have expected it, but he assumed that the stories were exaggerating. Unfortunately, that was not the case.

They were _downplaying_ the depths of Gilles' insanity.

Atrum had strongly considered using a Command Seal to just make Caster kill himself, but never actually committed to it. For everything, Gilles didn't seem to have any plans of betrayal and was genuinely working on winning the Holy Grail War.

He just wished that he would stop making "art" out of the human sacrifices and then showing it to him.

* * *

While returning from the church (after having fended off Berserker), Shirou Emiya and his Servant were met by Gilles.

"Oh, Jeanne." He cooed, causing Saber to raise her sword and step between him and her Master. "Is this what has become of you?"

"Servant Caster." Saber stated. "What business do you have with me?"

"Jeanne... do you not remember me?" Gilles asked. "Has God stolen your memories from you?"

"I am not the woman you think I am, Caster."

"Oh, my Holy Virgin, I will restore your memories. Even if it takes the power of the Holy Grail, I will not rest until your memories have been returned to you!"

Saber attempted to strike, only to instead hit nothing as Gilles warped away.

Shirou decided he did not like that Caster guy.

* * *

In spite of everything, Atrum decided that Gilles was actually a fairly effective Servant for his purposes. The grimoire that served as his Noble Phantasm allowed him to summon an effectively infinite army of monstrosities that could at least slow down a Servant if not kill them with enough numbers.

"Atrum, what do you think I should do? Jeanne doesn't recognize me, and I think God has stolen her memories."

Atrum was silent for almost thirty seconds. What the hell do you _say_ in response to that? But, this was a chance to get Gilles to do something useful.

"Send those monsters after her, and see if that jogs her memory." He ended up saying.

"Ah, yes, that is perfect. Thank you, Atrum!" Gilles said, warping away.

Atrum grabbed a bottle of booze from his desk. He was going to need it and a lot more if he was going to have to deal with his Servant.

* * *

Gilles, for all of his insanity, wasn't stupid. He knew that merely sending the monsters after Jeanne would not jog her memory. Atrocities were needed to remind her of who she was, the Holy Virgin of legend.

So he kidnapped several children first, hypnotizing one to send the message to Jeanne, and then simply hid out in a forest.

Jeanne came alone, as expected. That boy she called 'Master' was nothing more than an annoyance to Gilles, and would simply get in the way of their time together.

"Release those children immediately, Caster." Jeanne ordered.

"But why, Holy Maiden Jeanne? Our fun is only beginning!" Gilles said, summoning a small army of monstrosities. They instantly killed one of the children, spraying his blood across the forest floor.

Jeanne moved like wind, slicing through a monster before rushing for Gilles. Two more moved in, forcing her to get back as they struck with their tentacles. Gilles vanished, leaving the children to run and panic in the chaos.

Only one of the children survived. The despair and rage on Jeanne's face was... enjoyable, but not what Gilles was after. She didn't seem any closer to remembering her true self.

* * *

Gilles paced around in Atrum's office, babbling to himself about methods of restoring Saber's memories.

It had been about two days since the last meeting with Saber, and about two days of having to deal with Caster for Atrum. By this point, the Mage had managed to drink through a fairly large portion of his rather sizable selection of liquors.

Some small, not completely wasted, part of his mind worried for his liver. That part was quickly silenced by Atrum downing an entire bottle in an attempt to better deal with Gilles.

"Maybe you..." Atrum hiccuped. "Need a bigger atrocity? Something really..." Another hiccup. "Big. Scary. _Murderiffic_."

Gilles stopped pacing. Something clicked in his mind.

An idea formed. Well, calling it an idea was being generous to the Servant.

* * *

He headed down to the Mion River that night to summon the greatest monster in his grimoire. To reenact the horrors of war that created his Holy Virgin, he would summon the most terrifying beast he could and recreate those horrors with it.

Gilles de Rais manically cackled as it took him. It was the greatest horror that this Holy Grail War would ever see.

At least, he believed it to be that way. It took him in, using him as its core.

* * *

The first Servant to arrive on the scene was Saber, along with her Master. She looked up at the horrific beast Caster had summoned, standing on the river bank.

"What... _is_ that thing?" Shirou questioned. A reasonable question, given the circumstances. It was a minor mercy that fog covered much of its form, making it hard for those who weren't Mages to see it. And also obscuring its disgusting form, which was appreciated by all.

"I can only assume this is Caster's doing." Saber stated. She wasn't entirely certain what he was trying to accomplish, summoning such a great monster in the middle of the city, but she didn't like this. Especially with the tendon in her left thumb still severed, she couldn't use her Noble Phantasm if things came down to it. "Shirou, I will be engaging this monster directly. Summon me with a Command Seal if you are attacked."

"How are you going to get at it?" Shirou asked. Once again, he was asking a fairly reasonable question, given that the beast was on the water.

"I have been blessed by the Lady of the Lake. Water can never impede my movement, no matter where it may be." Saber answered, before leaping off into battle. She landed on the water as if it were a solid surface, sprinting along it towards her opponent.

Tentacles writhed as she approached, lashing at her and forcing her onto the defensive. She sliced through two easily, retreating from the third in an attempt to find a better angle of approach. It pursued her, getting slashed apart for its trouble. Nothing about this seemed right.

The next tentacle moved faster than the previous ones, wrapping around one of her arms before she could react.

Before she could act, Rider sped through, slicing the tentacle and freeing Saber.

"Rider, I appreciate the assistance." Saber said. She stepped back, dispatching another pair of tentacles that approached.

"Consider it payment for your Master hosting our banquet the other day!" Rider said, charging through the tentacles with his chariot. Saber spotted an opening, rushing in and slashing the beast itself. Her blade managed to cut through just fine, but the sheer amount of meat the beast had meant that she didn't do any real damage. Said damage regenerated anyway.

Caster's monster was going to be even tougher than anticipated. "Rider, do you have a method of destroying this beast in one blow?" Saber called out, jumping over a tentacle and running up the monster's body in an attempt to find a weak point. Nothing, and she eventually jumped off and landed back on the water.

"Unfortunately, my Noble Phantasm doesn't have the power for this!" Rider answered, continuing to tear at the beast's tentacles with his chariot and sword. The damage regenerated about as fast as Rider inflicted it, doing effectively nothing.

That was the true problem with Caster's monster. While it was strong, pretty much every Servant in the war was faster than its strikes when they were on guard, and it didn't truly do much damage with its blows. But it was simply too durable for anything the present Servants could do.

Saber spotted a golden streak speeding through the sky, pursued by a dark shadow. Archer must have been engaged in combat with... was that Berserker who commandeered a fighter jet?

That raised more questions than answers regarding who Berserker was. Questions that would have to be saved for later, for when Caster was finally defeated.

* * *

Shirou watched the battle, feeling a whirlwind of emotions course through him.

Feelings of worry for Saber and Sakura (wherever she was). Feelings of uselessness. And feelings of anger.

That monster was, as Saber told him, most likely powered by harvested magic from hundreds of people. And it was going to only kill more if they couldn't beat it.

He needed a weapon. A weapon that could break through the monster and strike at its heart. Something clicked in his mind, like the teeth of gears slotting into each other as they spun.

Archer could do it, bring weapons with him wherever he went. Sure, it was based on a faulty assumption, but shouldn't Shirou be able to do it too?

" _Trace, on_."

He had the exact image of the weapon he wanted to recreate. Lancer's Gae Dearg. All that was left was to make in reality. He hypothesized the structure. Guessed the material. Assumed how the curse it bore worked. He had no concrete information on the weapon he was trying to make, but it didn't matter. All he had to do was imagine it.

Rin ran over to him, heading to him to strategize. She was given a front row seat to Shirou's first ever Projection. "Emiya..." She muttered, staring in shock. He had more potential than she realized.

The first attempt fizzled out. He didn't put in enough power into its construction.

His Magic Circuits burned. It was now or never. Saber couldn't use her Noble Phantasm, Archer was preoccupied fighting Berserker, and Rider simply couldn't destroy the monster.

It appeared in his hand. Gae Dearg, a weapon capable of piercing all magic on its way to the target. And that monster was a magical being in its construction. Now all that's left was to attack.

He used his Reinforcement magic to strengthen his arm. This was it. If he failed, there was no chance of him creating a new one for another day at least. By then, Caster would have won. He spun around to gather momentum, before throwing it with all his might.

Shirou didn't once have thoughts of missing. For him, striking his target was assured.

This time was no different. It soared across the sky, piercing through the beast's flesh like it wasn't even there.

Within his monster, Caster looked down at his chest to find the cursed lance had struck his heart.

"Jeanne... I'm sorry..."

He faded away, taking his monster with him.

* * *

Within his office, Atrum had watched the entire battle. The outcome was... disappointing, but at least he had survived it. The Mage's Association would almost certainly treat him even greater than before for just surviving a Holy Grail War.

A dark shadow entered, completely silent. Atrum turned around, just in time for the shadow to stab him in the chest.

Assassin left without a trace, their Master's bidding done.


	3. Assassin

**Notes for the Chapter:**

> By this point, I should inform you all that I have not read Heaven's Feel yet, so I apologize if I get any information wrong.

The Command Seals had appeared on Shinji's hand before the war started.

As one can imagine, Shinji Matou was incredibly excited to have been chosen to be a Master in this Holy Grail War. Between him and Sakura, the war was as good as won and he could have any wish he desired.

However, he would never be allowed to have a Servant.

Zouken Matou had decided that he needed a Servant of his own, and saw a one ripe for the taking.

* * *

The summoning was a simple ordeal. After taking Shinji's Command Seals and using a Catalyst he had prepared prior to the war, Zouken summoned the Hassan of a Hundred Faces.

The perfect Servant for his purposes, one built for reconnaissance and interfering in other Masters' business. An Assassin-class Servant with abilities tailored for his purposes.

He had everything he needed to win.

* * *

While the Hassan of a Hundred Faces had many personalities, and thus different opinions, they were all united in one thing.

They weren't happy with their Master.

Not his cowardly nature, that was to be expected and was preferred for the Master of an Assassin. It was the fact that he was pure evil.

They have committed many sins during life, and will commit many more during the war. Truthfully, they felt they were the last who should be judging another for their sins.

But when it involved a girl that young suffering so much? That crossed a line.

However... Zouken was a fine supplier of mana. So, for the time being, he lives.

* * *

They had discovered of the Shadow fairly early on. It was in the forest near Ryuudou Temple, a fine place for any Servant-like creature to gather mana off the spirits heading there.

It was only through their Presence Concealment that they weren't immediately detected and consumed by the creature. Even still, it clearly sensed that someone was there, and lashed out with its tendrils in an attempt to catch its prey.

Zouken seemed to understand what that _thing_ was, even if he didn't tell them.

He also suggested using it to deal with troublesome Servants.

This was a plan that Assassin agreed with. For all his sins, his tactics were sound.

The first to fall to the Shadow was Lancer. Tricking him was easy. But... they lost over thirty of their personalities to his cursed lance that won't return, even with his death.

That still left them with the other seventy or so, but they still felt a pang of mourning for their fallen comrades. Even if said comrades were them.

* * *

Their next victory came after the Mion River Battle.

They managed to capture Shirou Emiya, bringing him to the Ryuudou Temple. Saber, Archer, and Rider both pursued, right as planned.

Interestingly, only Archer's Master had come with them. It was strange for Rider's Master to have not come with, given her attachment to Shirou Emiya and her Servant's tendency to bring her along with him to the battlefield.

The battle seemed one-sided to the uninformed. Three Servants versus one, plus a powerful Mage.

This was exactly as Assassin wanted them to think. The Shadow was heading here right now, and its arrival would spell the demise of four thorns in Assassin's side.

They sent out merely five to keep them occupied. Shirou Emiya was too exhausted after last night to fight back, so that meant the battle was technically five against four.

It was chaos in an instant. Archer's barrage of Noble Phantasms was easily taking care of two at once, Saber was only kept at bay by her lack of a steady mana supply, and Rider was trying to interrogate the two he was fighting.

That last part was informative. So, Sakura Matou had gone missing, and even Rider could not sense her? Even Assassin was surprised to discover that information.

The chaos was quickly replaced by calamity as the Shadow arrived. Assassin began to make their escape, only for Saber to pursue. Rider was currently making his own escape with the Masters of Saber and Archer on his chariot (much to the very loud protests of Archer).

That meant that Assassin and Saber were alone with the Shadow. It was in hot pursuit of them, rushing down the temple steps to consume them.

This wasn't the worst thing, but Assassin worried for what would happen when that thing consumed one of their personalities. So, Assassin decided that survival came first. Saber would either die to the Shadow, or would escape.

Either way, Assassin would make it out. That was more important than defeating another Servant with the Shadow hot on their heels. 

Saber proved to be faster than anticipated. Even with the tendon in her left thumb severed and low on mana, she was still more than enough to take down Assassin. She caught up, severing one of Assassin's arms in one slash.

Assassin decided to take a risky move. They knew that this personality was going to die anyway, and the Shadow would consume them. So they simply spun around and tackled Saber into the Shadow.

A distant Assassin watched as the Shadow consumed their other personality, and did _something else_ to Saber. They ran, not wanting to be spotted by the Shadow.

* * *

Kirei Kotomine was going to be their final opponent. It had been days since the fight at Ryuudou Temple.

A battle expected to be easy turned out to be terrifyingly dangerous.

Not only was Kirei borderline superhuman in ability, but he had that accursed lance that had taken so many of their personalities. He wielded it along with his Black Keys, switching it from hand to hand to keep them from tracking it as easily.

Every single remaining personality manifested, ready to defend their Master and defeat the one standing before them.

Kirei threw a Black Key, pinning one to a tree. The others moved, rushing at Kirei. He cut through them, each slash dispatching a body. Kirei's movements were precise, not a single wasted strike. He expanded the blades of his Black Keys, using the unexpected increase in range to catch two off-guard.

Truthfully, it was impressive to see a mere man keep up with them in this way. A Servant was supposed to be unbeatable by a human, no matter what.

Kirei didn't care much for rules like that. He hurled Gae Buidhe along with two Black Keys, opening up a path in the horde of Assassins. He rushed through it at utterly inhuman speeds, grabbing Gae Buidhe from the ground where it landed.

Each Assassin slowly met the same fate, getting killed by Gae Buidhe's curse and forced out of battle permanently. Perhaps if that lance was destroyed, their fallen comrades would return, but that would require them to be able to beat Kirei.

Kirei reached their Master, hurling all of his remaining Black Keys as well as Gae Buidhe to cover himself as he prepared to end Zouken's life permanently.

The battle had been lost, and Assassin faded away not long after. There was simply no point in bothering with killing Kirei. Zouken was dead, and there were no Masters left to take them on.

The priest smiled.


	4. Berserker

Illyasviel von Einzbern looked up at her Servant. Lancelot of the Lake, summoned in the Berserker class, simply kneeled as he would have for his king.

She giggled.

* * *

They found Shirou Emiya outside the church. He was joined by the Tohsaka and the Matou representatives. All three had Servants, as Illyasviel expected. Well, she didn't quite expect Shirou to have a Servant, but it wasn't a surprise.

"Hello, big brother." She said. "My-"

Lancelot materialized before Illya could finish her sentence, lunging at Saber. He pulled a light pole from the ground, corrupting it with his Noble Phantasm, and swung it at her.

Saber brought up her blade, meeting Lancelot's attack with one of her own. Much to her surprise, Lancelot's improvised weapon didn't even bend, much less break. Saber skidded across the pavement, Lancelot madly pursuing her.

"Mongrel, who gave you permission to touch my Saber?" Archer questioned, opening up portals behind him and firing a barrage of weapons at Lancelot.

Lancelot's response to Archer's attack was to dodge the first weapon (a simple straight sword), grabbing it out of the air as it passed him and corrupting it with his Noble Phantasm, and then deflect the rest with it. He continued to rush at Saber, who met his stolen blade with her own.

Despite being empowered by Mad Enhancement, Lancelot retained a disturbing amount of skill with a sword. Saber was easily being pushed back by the brutish knight, finding his swordsmanship to be oddly familiar. It didn't match up perfectly with any fighting style she's encountered, but it was definitely a style she encountered prior to her opponent's descent into madness.

Saber parried a blow, landing a counterattack that forced Lancelot back. Archer unleashed another barrage, forcing both Saber and Lancelot to get moving.

"Archer, you're not helping!" Saber shouted, parrying another strike before having to get back as Archer kept up the assault that was singlemindedly focused on killing Berserker. At that point, Saber just decided to focus on getting out of the line of fire rather than trying to actually fight Lancelot.

Eventually, the chaos died down as Archer stopped his bombardment. In spite of everything, Lancelot was still standing and ready to fight.

"Oh, what a pity." Illya said. "It seems neither of you managed to beat Berserker."

Berserker lunged at Saber once more, swinging his stolen weapon at her with all the force of a bomb.

"Saber!"

It hit Shirou as he pushed Saber out of the way, cleaving out a chunk of his side before Illya forced Lancelot to retreat. Archer prepared to attack Berserker anyway, only for Rin to scream at him to stop and just let them go so she wouldn't have to worry about them attacking her while she was dealing with Shirou. She already saved the idiot once today, she wasn't going to let him die a second time.

"Senpai!"

Shirou lost consciousness, seeing Rider's Master running for him.

* * *

Illyasviel ended up meeting Shirou personally for the first time two days later.

She had been wandering around Fuyuki, taking in sights she'd have never seen otherwise (while Lancelot slept back at the castle, because she wasn't going to give him the chance to go berserk while she was having fun), and headed out near a market that bordered a neighborhood.

And then she saw him and decided to bother him.

Much to Illya's surprise (even if she hid it), Shirou was a much better person than she expected.

"Do you know who Kiritsugu Emiya is?" Shirou asked, near the end of their meeting.

Illya stood up. "I do. He's..." _my father._ "Someone important to making me the lady I am."

* * *

Most of the rest of the Holy Grail War had very little directly happen to Illya. She had met with Shirou a couple more times (completely unbeknownst to his allies), and had spoken of a certain legend in her family, but didn't do much else. While she had sent Berserker out during the Mion River Battle (originally to take on Caster, only for him to attack Gilgamesh instead), he hadn't done anything and she wasn't seen.

And then Saber, corrupted by the Shadow, attacked the Einzbern mansion.

Lancelot didn't go berserk on sight against her. He didn't even recognize her in this state.

"Berserker, give her everything you've got!" Illya ordered.

The dark aura around Lancelot faded, as he drew his sword.

" _Arondight_." Saber noted, readying her corrupted Excalibur. "I had wondered why I recognized your swordsmanship."

Lancelot lunged, clashing blades with Saber. Their first blow was like an explosion, shattering the tiles below them. Saber pushed off, countering with a heavy slash that Lancelot only barely managed to block. They clashed again and again, each encounter ending in Saber dealing more damage than anything Berserker could inflict.

The next clash sent Lancelot flying, crashing through several walls. Saber calmly walked through the destruction, approaching Lancelot without much worry. Lancelot picked himself up, gripping his sword with one hand. The other hand grabbed a piece of rubble, hurling it at Saber.

She instinctively swatted it out of the air, which gave Lancelot a tiny opening, allowing him to land an overhead strike that shattered her helmet. Seeing her face directly, he only grew more aggressive from there.

Blade met blade again, only for her Saber to actually be pushed back by the strike instead of blocking and countering with ease. Lancelot almost seemed to smile beneath his helmet, as he went onto a brutal offensive.

Saber's sword burned with a dark aura, as she blocked the next strike. She had held back out of respect for a comrade. But that was over. Saber parried the follow-up strike, thrusting her blade and stabbing Lancelot in the chest.

The Shadow arrived not long after, corrupting him.

* * *

Berserker's final battle arrived not long after. While Kirei Kotomine was battling with Assassin and Zouken Matou, Shirou and Illya were forced to try and contend with the mad knight.

Shirou projected a pair of short swords, attempting to keep Berserker's attention away from Illya. He threw one ( _Kanshou,_ some part of his mind told him), which clanked off Berserker's armor. Shirou wasn't deterred by this, even though he should be, and approached Berserker as he made a step in Illya's direction.

He struck with the other blade ( _Bakuya_ , his brain told him), which didn't even scratch Berserker's armor. But it drew his attention, which was all Shirou needed. Berserker turned, swinging his sword wildly at Shirou.

Shirou brought up his blade, strengthening it as much as possible before Arondight could strike it. The effort reduced it from cleaving him in half to just causing Bakuya to shattered and send Shirou tumbling across the forest floor.

The boy barely managed to pick himself up, seeing Berserker charging at him. This was it. He had to do _something_ , or Berserker would reduce him to a red paste in the next strike.

" _So, you can Project weapons?_ " He remembered Archer's words. " _What an adorable attempt at imitating my Noble Phantasm. But it will never reach that level, not even if you had all the time in the universe to train._ "

He couldn't _stand_ that guy, even with their alliance. Shirou grit his teeth, beginning to Project his next weapon. There was one right in front of him that should do just fine.

' _I don't need to reach your level! I just need to be stronger than whatever's in front me!_ ' He mentally declared, raising a hand to the sky. His Magic Circuits burned, straining under the stress of this Projection. He was Projecting a Noble Phantasm on par with Gae Dearg.

It felt more natural in spite of that. Swords were more natural to him than that spear.

Berserker was one meter away. Shirou smiled, as the weapon took form in his hand.

Arondight met Arondight. While Shirou's copy was inferior, it also wasn't damaged by clashing with a stronger Servant yet. As such, both weapons met without destroying each other. Berserker was off-balance for an instant, almost surprised by this development.

Shirou barely managed to follow up, even as his arms felt like they were going to explode. He only needed to land one blow, as long as it killed. One rising slash struck Berserker's armor, cleaving through it and opening up a vicious gash.

Lancelot fell to his knees, helmet falling from his head and fading away. He looked Shirou in the eye.

Shirou walked past Lancelot to check on Illya.

"I'll protect her." He assured, as Lancelot faded away. "I promise."


End file.
